Process for molecular-specific optical fiber probes for raman detection

Abstract

A process for indicator coating of SERS fiber-optic probes comprising selecting a potentially roughened probe which is enhanced with a deposited silver film and then treated by chemisorption on said probe to form a molecular-specific coating, such as by employing Eriochrome Black T for metal ions, octadecyl mercaptan for organics, or Cresol Red for pH.

We claim: 
     
       1. A process for molecular-specific coating of SERS fiber-optic probes comprising: providing a fiber-optic SERS probe;   providing a molecular-specific coating; and   bonding by chemisorption, absorption, or adsorption said molecular-specific coating onto said probe.   
     
     
       2. The process according to claim 1 wherein said molecular-specific coating further comprises a Raman indicator compound for ions. 
     
     
       3. The process according to claim 2 wherein said ions further comprise the alkaline earth metal ions. 
     
     
       4. The process according to claim 3 wherein said metal ions comprise calcium, magnesium, barium, strontium, copper or lead. 
     
     
       5. The process according to claim 2 wherein said Raman indicator consists essentially of Eriochrome Black T. 
     
     
       6. The process according to claim 1 wherein said molecular-specific coating further comprises amphiprotic compounds as a Raman pH indicator. 
     
     
       7. The process according to claim 6 wherein said amphiprotic compounds comprise Cresol Red, Methyl Red, or 4-pyridine thiol. 
     
     
       8. The process according to claim 6 wherein said Raman pH indicator consists essentially of Cresol Red. 
     
     
       9. The process according to claim 1 wherein said molecular-specific coating further comprises a partitioning compound for organic molecules. 
     
     
       10. The process according to claim 9 wherein said partitioning compound for organic molecules further comprises alkyl thiols. 
     
     
       11. The process according to claim 10 wherein said alkyl thiols consists essentially of octadecyl mercaptan. 
     
     
       12. The process according to claim 9 wherein said organic molecules comprise xylenes, benzene, p-dichlorobenzene, or naphthalene. 
     
     
       13. The process according to claim 1 wherein said bonding by chemisorption, absorption, or adsorption said molecular-specific coating onto said probe further comprises requiring the difference in SERS bands associated with the coating and the coating/analyte complex be proportional to quantitative amounts of the analyte. 
     
     
       14. A process for Raman indicator coating of SERS fiber-optic probes comprising: providing a SERRS probe roughened to about 32 micrometers and film deposited to about 15 to 60 nm mass thickness with silver; and   chemisorping a molecular-specific coating on said probe.   
     
     
       15. The process according to claim 14 wherein said molecular-specific coating further comprises Eriochrome Black T as a Raman indicator for metal ions. 
     
     
       16. The process according to claim 15 wherein said metal ions comprise calcium, magnesium, barium, strontium, copper or lead. 
     
     
       17. The process according to claim 14 wherein said molecular-specific coating further comprises octadecyl mercaptan as a Raman partitioning compound for organic molecules. 
     
     
       18. The process according to claim 17 wherein said organic molecules comprise xylenes, benzene, p-dichlorobenzene, or naphthalene. 
     
     
       19. The process according to claim 14 wherein said molecular-specific coating further comprises amphiprotic compounds as a Raman pH indicator. 
     
     
       20. The process according to claim 19 wherein said amphiprotic compounds comprise Gresol Red, Methyl Red, or 4-pyridine thiol. 
     
     
       21. The product produced according to the process of claim 1. 
     
     
       22. The product produced according to the process of claim 14. 
     
     
       23. A process for molecular-specific coating of SERS fiber-optic probes comprising: providing a fiber-optic SERS probe with a roughened surface subsequently covered with thin metal film;   providing a molecular-specific coating; and   bonding by chemisorption, absorption, or adsorption said molecular-specific coating onto said probe.   
     
     
       24. The process according to claim 23 wherein said roughened surface comprises using polishing paper containing alumina particles of about from 0.3 to 32 micrometers in roughness. 
     
     
       25. The process according to claim 23 wherein said thin metal film further comprises gold, silver, or copper. 
     
     
       26. The process according to claim 23 wherein said thin metal film further comprises a mass thickness of about 15 to 60 nm.